Half-Cycle Atomic Layer Deposition Reaction Study Using O3 and H2O Oxidation of Al2O3 on In0.53Ga0.47As

The effect of water and ozone as the oxidant in the atomic layer deposition (ALD) of aluminum oxide on the ammonium-sulfide-passivated In0.53Ga0.47As surface is compared using X-ray photoelectron spectroscopy (XPS) after each half-cycle of the ALD process. While the first half-cycle of the aluminum precursor tri-methyl aluminum (TMA) reduces the residual native oxides to within detection limits of XPS, the ozone oxidation process causes significant reoxidation of the substrate in comparison to the water-based process. Subsequent TMA pulses fail to remove the excess interfacial oxides caused by ozone oxidation, resulting in the formation of an oxide interlayer.